A Scorpion with an Elite on its gunner seat shoots off screen. Cuts to a red Spartan-III performing an assassination on a steel-colored Spartan-III. Cuts to three blue Spartans cornering a red Spartan in a room inside Powerhouse. A pair of Elites run down the steel bars, one using the Armor abilitiesevade as he lands on the ground. Cuts again to another part in Powerhouse, two Spartans run into the center of the map. Cuts to three red Spartan killing a blue Spartan on Sword Base's ground floor.

Cuts to the HUD of a blue team Spartan playing a Team King of the Hill match in Powerhouse, defending the hill from three red Spartans. Cuts again to a red Spartan flying out from one of the rooms in Sword Base, firing his Assault Rifle. Cuts back to Powerhouse, a mixed battle between red team and blue team, many of them using the jetpack. Cuts to the HUD of a blue team Spartan killing a red Spartan during a Capture the Flag match with a Frag grenade. Cuts to the HUD of a Shotgun-wielding Spartan-III during an Invasion match on Boneyard, narrowly escaping from a Ghost using Armor Lock, destroying the Covenant vehicle in the process. Cuts to the HUD of a blue team Spartan-III killing a flying red Spartan-III using his M6G pistol in a King of the Hill match. Cuts to Sword Base again, a third person view of a Spartan player sprinting to the Gravity lift, changing to his HUD as he levitates up. Cuts back to Powerhouse, a blue Spartan-III manages to kill a flying red Spartan-III with his Rocket Launcher. Cuts back to Sword Base into the HUD of a camouflaged Sniper-wielding green Spartan, no-scoping at a red Spartan-III's head.

Cuts to the showers in Powerhouse, a Spartan player performing assassination on another player. A word appears behind them:

ASSASSINATION

Cuts to an Elite player being assassinated by a Spartan-III player during an Invasion match. Cuts to a few red team Spartan-III players defending the blue flag from blue team in a CTF match on Powerhouse. Cuts to a chaotic battle in Sword Base, with plasma grenade explosions and Needle rifle fires. Cuts to a Spartan-III player playing CTF in a tight corridor inside Sword Base, getting caught in explosions with his teammates. Cuts to Powerhouse, red team players are fighting enemies who are off-screen. Cuts to a Phantom landing in Boneyard.

Cuts to Boneyard, a Wraith, a Banshee, a Ghost and two more players on foot firing at enemies off-screen. A word appears in front of them:

INVASION

Cuts to numerous Spartans charging towards Elites in an Invasion match on Boneyard, a few dying from plasma and Needler fire. Switches to an overhead view, the firefight continues. Cuts to the HUD of a Spartan-III in an Invasion match wielding a Grenade Launcher watching a Banshee explodes. Cuts to a zoomed-in scope of a player's HUD, head-shotting a Spartan-III. Cuts to the HUD of a Plasma Launcher-wielding Elite player, locked on a Warthog, firing plasma grenade-like bolts at the Human vehicle. Switches to a third person view, the Warthog explodes. Cuts to two Elite players, one evading after being harmed by a grenade.

Cuts to Sword Base, a player dies and falls on one of the bridge, flaming skulls falling around him. A word appears under the transparent bridge:

Cuts to the HUD of a DMR-wielding Spartan-III player, headshotting another player, resulting in drops of flaming skulls from the dead body. Cuts to overhead view of a Headhunter match on Powerhouse, one player killed with an M6G pistol and a flaming skull falls out. Cuts to a room in Powerhouse, a player gets killed, and three flaming skulls fall outs.

Cuts to three blue Spartan-IIIs running into a room inside Powerhouse, explosions engulfs them and words in front of them:

ACTIVE ROSTER

Cuts to four red Spartan-IIIs running out from a corner of a building, firing their weapon. Cuts to a Sniper-wielding player walking on one of the bridges in Sword Base, killing another player who is in the corridor. Cuts to another room in Sword Base, a red team player stands beside a blue flag. Cuts to the HUD of a Grenade Launcher-wielding player ambushing an unaware Gravity Hammer-wielding player who just enters the building. Cuts to the exterior of Powerhouse, a flying red team Spartan-III fires his Assault Rifle. Switches to his HUD, and he kills a blue Spartan-III player.

Cuts to the building in Overlook, a Spartan team and Elite team clashing in front of it. Words appear on the building:

SPARTANS VS. ELITES

Cuts to a Warthog in Boneyard, the Spartan on the M41 Light Anti-Aircraft Gun fires at two Elite players. Cuts to Overlook, an Elite destroys a Generator using its Rocket Launcher in Generator Defense, killing the Spartan-IIIs guarding it. Cuts to a Banshee flying overhead in Boneyard. Cuts to the ground, a Scorpion explodes under the fire of a Fuel Rod Cannon.

Cuts to the area "Control Center" in Sword Base, a battle between two red team player and two blue team players. Zooms into the computers, words can be seen:

Cuts to the HUD of a player in Team Slayer on Powerhouse, killing another player with a head shot using his M6G pistol. Cuts to the roof of a room in Powerhouse, a red Spartan-III player fires his Focus rifle at an enemy at the far end of the map. Cuts to the HUD of the scope of an M6G pistol, the player kills another player with a headshot. Cuts to a red team player killing a blue team player who just killed another red team player with a melee in Sword Base. Cuts to Sword Base, to the HUD of a blue team Spartan-III jumping down from a bridge, killing a red team player in the fall with his DMR. Cuts to Powerhouse, a red team player beats down a blue player with his Gravity Hammer. Cuts to the HUD of blue team player killing a red team player with a headshot using his M6G on Powerhouse. Cuts to the HUD of a flying blue team player killing another flying red team player using his Energy Sword. Cuts to a team of Spartan-IIIs charging at a group of Elites, backed up by their Scorpion and Warthog behind them.

Cuts to Spartan lands on the steel bar in Powerhouse and throws a grenade. The explosion covers a date for a moment, then view zooms in to the date after the explosion:

Even though the trailer promotes the Beta, the code at the right lower corner reads "Reach_Alpha", indicating the trailer is recorded using the Halo: Reach Alpha version. This is also apparent in the shown user interface graphics, which differ from the ones in Beta and released version.